The design is a double-blind, two period cross-over study comparing topiramate to placebo. Patients will be called twice a week to individually titrate doses of topiramate towards a maximum of 800 mg per day and monitor side effects. The primary outcome measures in this study will be the daily pain scores in the low back, in the leg and combined. Patients' quality of life and activities of daily living will be secondary outcome measures as assessed by the SF 36, Oswestry, and Beck questionnaires. Sixty five patients will be enrolled in this study and the duration of the study will be 17 weeks, including one week baseline, four week escalation, two week maintenance and two week wash out for topiramate and placebo respectively.